“…However, most of the extant studies mainly focused on examining the shadow prices of waste gases (i.e., sulfur dioxide, carbon dioxide and nitrogen oxides), e.g., Ke et al (2008), Lee and Zhang (2012) and Wang and Wei (2014). Ke et al (2010) in their study have explored the shadow prices of industrial waste gas, wastewater and solid waste in China, but they have not investigated water efficiency and the shadow prices of main pollutants in wastewater (i.e.,. In addition, the most previous studies use the radial efficiency measures that cannot capture all the technical inefficiency in inputs, desirable outputs and pollutants.…”